package cn.iocoder.yudao.framework.common.util.servlet;

import cn.hutool.core.io.IoUtil;
import cn.hutool.core.util.StrUtil;
import cn.hutool.extra.servlet.ServletUtil;
import cn.iocoder.yudao.framework.common.util.json.JsonUtils;
import org.apache.commons.lang3.StringUtils;
import org.springframework.http.MediaType;
import org.springframework.web.context.request.RequestAttributes;
import org.springframework.web.context.request.RequestContextHolder;
import org.springframework.web.context.request.ServletRequestAttributes;

import javax.servlet.ServletRequest;
import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.Part;
import java.io.IOException;
import java.net.URLEncoder;
import java.util.Map;

/**
 * 客户端工具类
 *
 * @author 芋道源码
 */
public class ServletUtils {

    /**
     * 返回 JSON 字符串
     *
     * @param response 响应
     * @param object 对象，会序列化成 JSON 字符串
     */
    @SuppressWarnings("deprecation") // 必须使用 APPLICATION_JSON_UTF8_VALUE，否则会乱码
    public static void writeJSON(HttpServletResponse response, Object object) {
        String content = JsonUtils.toJsonString(object);
        ServletUtil.write(response, content, MediaType.APPLICATION_JSON_UTF8_VALUE);
    }

    /**
     * 返回附件
     *
     * @param response 响应
     * @param filename 文件名
     * @param content 附件内容
     */
    public static void writeAttachment(HttpServletResponse response, String filename, byte[] content) throws IOException {
        // 设置 header 和 contentType
        response.setHeader("Content-Disposition", "attachment;filename=" + URLEncoder.encode(filename, "UTF-8"));
        response.setContentType(MediaType.APPLICATION_OCTET_STREAM_VALUE);
        // 输出附件
        IoUtil.write(response.getOutputStream(), false, content);
    }

    /**
     * @param request 请求
     * @return ua
     */
    public static String getUserAgent(HttpServletRequest request) {
        String ua = request.getHeader("User-Agent");
        return ua != null ? ua : "";
    }

    /**
     * 获得请求
     *
     * @return HttpServletRequest
     */
    public static HttpServletRequest getRequest() {
        RequestAttributes requestAttributes = RequestContextHolder.getRequestAttributes();
        if (!(requestAttributes instanceof ServletRequestAttributes)) {
            return null;
        }
        return ((ServletRequestAttributes) requestAttributes).getRequest();
    }

    public static String getUserAgent() {
        HttpServletRequest request = getRequest();
        if (request == null) {
            return null;
        }
        return getUserAgent(request);
    }

    public static String getClientIP() {
        HttpServletRequest request = getRequest();
        if (request == null) {
            return null;
        }
        return ServletUtil.getClientIP(request);
    }

    public static boolean isJsonRequest(ServletRequest request) {
        return StrUtil.startWithIgnoreCase(request.getContentType(), MediaType.APPLICATION_JSON_VALUE);
    }

    public static String getBody(HttpServletRequest request) {
        return ServletUtil.getBody(request);
    }

    public static byte[] getBodyBytes(HttpServletRequest request) {
        return ServletUtil.getBodyBytes(request);
    }

    public static String getClientIP(HttpServletRequest request) {
        return ServletUtil.getClientIP(request);
    }

    public static Map<String, String> getParamMap(HttpServletRequest request) {
        return ServletUtil.getParamMap(request);
    }

    public static String getRemoteIP(HttpServletRequest request) {
        String ip = request.getHeader("x-forwarded-for");
        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getHeader("Proxy-Client-IP");
        }

        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getHeader("WL-Proxy-Client-IP");
        }

        if (ip == null || ip.length() == 0 || "unknown".equalsIgnoreCase(ip)) {
            ip = request.getRemoteAddr();
        }
        return ip;
    }

    /**
     * Servlet3没有提供直接获取文件名的方法,需要从请求头中解析出来
     * 获取请求头，请求头的格式：form-data; name="file"; filename="snmp4j--api.zip"
     * 根据请求头解析出文件名
     * 请求头的格式：火狐和google浏览器下：form-data; name="file"; filename="snmp4j--api.zip"
     * IE浏览器下：form-data; name="file"; filename="E:\snmp4j--api.zip"
     */
    public static String getFileName(Part part) {

        String header = part.getHeader("content-disposition");

        if (StringUtils.isBlank(header)) {
            return null;
        }
        /*
          String[] tempArr1 = header.split(";");代码执行完之后，在不同的浏览器下，tempArr1数组里面的内容稍有区别
          火狐或者google浏览器下：tempArr1={form-data,name="file",filename="snmp4j--api.zip"}
          IE浏览器下：tempArr1={form-data,name="file",filename="E:\snmp4j--api.zip"}
         */
        String[] tempArr1 = header.split(";");
        if (tempArr1.length < 3) {
            return null;
        }
        /*
         火狐或者google浏览器下：tempArr2={filename,"snmp4j--api.zip"}
         IE浏览器下：tempArr2={filename,"E:\snmp4j--api.zip"}
         */
        String[] tempArr2 = tempArr1[2].split("=");
        if (tempArr2.length < 2) {
            return null;
        }
        //获取文件名，兼容各种浏览器的写法
        return tempArr2[1].substring(tempArr2[1].lastIndexOf("\\") + 1).replaceAll("\"", "");
    }

    public static String getCookieValue(HttpServletRequest req, String cookieKey) {
        if (req == null || StringUtils.isBlank(cookieKey)) {
            return null;
        }
        Cookie[] cookies = req.getCookies();
        if (cookies != null) {
            for (Cookie cookie : cookies) {
                if (cookieKey.trim().equalsIgnoreCase(cookie.getName())) {
                    return cookie.getValue();
                }
            }
        }
        return null;
    }


    public static void addCookie(HttpServletResponse resp, String key, String value, String domain, String path, Integer maxAge) {
        if (resp == null || StringUtils.isBlank(key)) {
            return;
        }
        Cookie cookie = new Cookie(key, value);
        if (StringUtils.isNotBlank(domain)) {
            cookie.setDomain(domain);
        }
        if (StringUtils.isNotBlank(path)) {
            cookie.setPath(path);
        } else {
            cookie.setPath("/");
        }
        if (maxAge != null) {
            cookie.setMaxAge(maxAge);
        }
        resp.addCookie(cookie);
    }
}
